Silicon anodes have attracted extensive attention for next-generation lithium-ion batteries owing to their exceptionally high theoretical specific capacity (3 579 mA∙h/g), nearly ten times that of conventional graphite anodes. However, their practical application remains severely hindered by the drastic volume expansion (up to 300%) during lithiation/delithiation, which induces electrode pulverization, interfacial instability, loss of electrical contact, and consequently rapid capacity decay upon cycling. Conventional copper foil current collectors, with their smooth surfaces, provide limited adhesion for the silicon layer and lack effective stress-buffering capability, further aggravating these degradation mechanisms. To address these issues, the work aims to propose a strategy involving femtosecond laser drilling to create ordered through-hole arrays on copper foil with a thickness of 8 µm, yielding a lightweight yet structurally functionalized porous current collector.
The fabrication process was systematically investigated by varying the pulse repetition rate (4, 6 and 8 kHz) while keeping the scanning speed (340 mm/s) and single-pulse fluence (8.49 J/cm2) constant, aiming to identify the optimal parameter window that balanced hole quality and foil integrity. The effects of these parameters on the macroscopic morphology and the formation of the through-hole array were examined. A pulse repetition rate of 4 kHz was found to be optimal, producing a flat, tear-free surface with regular hole arrangement. Scanning electron microscopy measurements revealed that the through-hole array exhibited entrance and exit diameters of (24.4±0.8) µm and (22.4±0.3) µm, respectively, with the conical profile attributed to the Gaussian energy distribution of the laser beam. The slight taper from entrance to exit suggested a gradual attenuation of laser energy during propagation through the foil thickness. Notably, no significant oxidation was detected on the processed copper surface, confirming the low thermal impact characteristic of femtosecond laser ablation.
The optimized porous copper foil was then employed as a current collector for silicon anodes, and its electrochemical performance was comprehensively evaluated via cyclic voltammetry, galvanostatic charge/discharge tests at various C-rates, and electrochemical impedance spectroscopy. The silicon anode incorporating this porous current collector delivered a remarkable reversible capacity of 2 601 mA∙h/g at 0.1 C, close to the theoretical value of silicon. After 100 cycles at 1 C, a capacity retention as high as 81% was achieved, substantially surpassing the 7% retention observed for the anode using pristine copper foil. Electrochemical impedance spectroscopy revealed that the charge transfer resistance of the porous-current-collector-based anode exhibited only marginal growth after cycling, whereas that of the conventional anode increased dramatically. Furthermore, the electrode-level specific capacity, accounting for the total mass of the electrode including active material, conductive agent, binder, and current collector, reached 116 mA∙h/g after 100 cycles at 1 C, significantly higher than most silicon-based anodes reported in the literature, highlighting the advantage of current collector lightweighting.
Post-cycling morphological analysis provided direct experimental evidence for a triple synergistic mechanism responsible for the enhanced performance. Firstly, mechanical interlocking between the silicon layer and the through-hole walls effectively prevented electrode delamination from the current collector. Secondly, the hole array dispersed localized stress induced by silicon volume expansion, thereby suppressing the initiation and propagation of macroscopic cracks. Thirdly, the porous architecture allowed electrolyte to access the electrode from both sides, simultaneously shortening Li+ diffusion pathways and increasing the number of electrochemically active sites. This work not only demonstrates a viable femtosecond laser processing route for lightweight porous current collectors but also provides mechanistic insights into the design of high-performance, long-life silicon anodes for high-energy-density lithium-ion batteries.
Key words
femtosecond laser /
laser machining /
porous copper foil current collector /
lithium-ion battery /
Si anode
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
References
[1] CAO L, ZHENG M, DONG G C, et al.Tailoring Nanoscale Primary Silicon in Laser Powder Bed Fusion for High-Performance Lithium-Ion Battery Anodes[J]. Journal of Materials Science & Technology, 2025, 211: 278-287.
[2] RIST U, PFLEGING W.Laser Printing of Silicon- Containing Anodes with Polyacrylic Acid[J]. Batteries, 2025, 11(5): 191.
[3] LI L Z, DENG Y, HU K K, et al.Nanostructure Designing and Hybridizing of High-Capacity Silicon-Based Anode for Lithium-Ion Batteries[J]. Progress in Natural Science: Materials International, 2023, 33(1): 16-36.
[4] LIU X H, ZHONG L, HUANG S, et al.Size-Dependent Fracture of Silicon Nanoparticles during Lithiation[J]. ACS Nano, 2012, 6(2): 1522-1531.
[5] WU H, CUI Y.Designing Nanostructured Si Anodes for High Energy Lithium Ion Batteries[J]. Nano Today, 2012, 7(5): 414-429.
[6] REYTER D, ROUSSELOT S, MAZOUZI D, et al.An Electrochemically Roughened Cu Current Collector for Si-Based Electrode in Li-Ion Batteries[J]. Journal of Power Sources, 2013, 239: 308-314.
[7] SU P F, ZHANG Z Q, LUO L S, et al.Cu Nanowire Array with Designed Interphases Enabling High Performance Si Anode Toward Flexible Lithium-Ion Battery[J]. Nano Research, 2024, 17(3): 1516-1524.
[8] REN Y B, ZHANG S C, ZHANG L C, et al.3D Si@Cu-Ni Nano-Pillars Array Composite as Carbon/Binder Free Anode for Lithium Ion Battery[J]. Journal of Materials Research and Technology, 2020, 9(2): 1549-1558.
[9] ZHANG Z L, WANG Z L, LU X M.Multishelled Si@Cu Microparticles Supported on 3D Cu Current Collectors for Stable and Binder-Free Anodes of Lithium-Ion Batteries[J]. ACS Nano, 2018, 12(4): 3587-3599.
[10] WANG L, ZHOU D C, ZHU J, et al.Advancing Silicon Anode in Pouch Li-Ion Batteries by Plastic Current Collectors with Surface Moieties[J]. Chemical Engineering Journal, 2025, 519: 165198.
[11] CHEN J C, YANG J, CHENG M M.Induced Nanoscale Roughness of Current Collectors Enhances Lithium Ion Battery Performances[J]. Journal of Power Sources, 2019, 430: 169-174.
[12] KIM Y L, SUN Y K, LEE S M.Enhanced Electrochemical Performance of Silicon-Based Anode Material by Using Current Collector with Modified Surface Morphology[J]. Electrochimica Acta, 2008, 53(13): 4500-4504.
[13] KIM J T, KENNEDY S, PHIRI I, et al.Plasma Surface Treatment of Cu Current Collectors for Improving the Electrochemical Performance of Si Anodes[J]. ACS Applied Materials & Interfaces, 2024, 16(9): 11400-11407.
[14] DUN X Y, WANG M Y, SHI H T, et al.Composite Copper Foil Current Collectors with Sandwich Structure for High-Energy Density and Safe Lithium-Ion Batteries[J]. Energy Storage Materials, 2025, 74: 103936.
[15] YUAN W, PAN B Y, QIU Z Q, et al.Using Orthogonal Ploughing/Extrusion to Fabricate Three-Dimensional On-Chip-Structured Current Collector for Lithium-Ion Batteries[J]. ACS Sustainable Chemistry & Engineering, 2019, 7(15): 12910-12919.
[16] FEI X Y, DONG Z C, GONG B K, et al.Lightweight Through-Hole Copper Foil as a Current Collector for Lithium-Ion Batteries[J]. ACS Applied Materials & Interfaces, 2021, 13(35): 42266-42275.
[17] TANG X X, LIU W, YE B Y, et al.Preparation of Current Collector with Blind Holes and Enhanced Cycle Performance of Silicon-Based Anode[J]. Transactions of Nonferrous Metals Society of China, 2013, 23(6): 1723-1727.
[18] HAN Y J, ZHANG J J, LIU Y, et al.Investigation of through Micropatterns Fabrication on C194 Copper Foil by Ultraviolet Nanosecond Pulsed Laser Microdrilling[J]. Optics & Laser Technology, 2023, 160: 109092.
[19] TUNNA L, KEARNS A, O’NEILL W, et al. Micromachining of Copper Using Nd: YAG Laser Radiation at 1064, 532, and 355 nm Wavelengths[J]. Optics & Laser Technology, 2001, 33(3): 135-143.
[20] LI Q S, SUN X F, MEI X S, et al.High-Quality Femtosecond Laser Cutting of Battery Electrodes with Enhanced Electrochemical Performance by Regulating the Taper Angle: Promoting Green Manufacturing and Chemistry[J]. Applied Energy, 2025, 377: 124452.
[21] MOORHOUSE C J, VILLARREAL F J, BAKER H J, et al.Laser Drilling of Copper Foils for Electronics Applications[J]. IEEE Transactions on Components and Packaging Technologies, 2007, 30(2): 254-263.
[22] PFLEGING W.A Review of Laser Electrode Processing for Development and Manufacturing of Lithium-Ion Batteries[J]. Nanophotonics, 2018, 7(3): 549-573.
[23] SUGIOKA K.Progress in Ultrafast Laser Processing and Future Prospects[J]. Nanophotonics, 2017, 6(2): 393-413.
[24] YU K C, SHI H C, ZHANG P L, et al.Micro/ Nanoengineering of Functionalized Metal Surfaces Based on Short/Ultra-Short-Pulsed Lasers: A Review[J]. Journal of Materials Science, 2024, 59(5): 1819-1866.
[25] PFLEGING W.Recent Progress in Laser Texturing of Battery Materials: A Review of Tuning Electrochemical Performances, Related Material Development, and Prospects for Large-Scale Manufacturing[J]. International Journal of Extreme Manufacturing, 2021, 3(1): 012002.
[26] XU M Y, GAO C W, TANG T W, et al.Rational Design of Micro-Cone Array on Copper Host for Dendrite-Free Sodium Metal Plating[J]. Chemical Engineering Journal, 2025, 510: 161679.
[27] RATYNSKI M, KRAJEWSKI M, TAMULEVIČIUS T, et al. Femtosecond Laser Treatment of Copper Current Collectors and Their Application in Li-Ion Batteries[J]. ACS Applied Engineering Materials, 2025, 3(9): 3228-3238.
[28] WU J R, GUO H X, WANG R X, et al.Fabrication of Low-Tortuosity Thick Electrodes with Low Material Loss by Temporally Shaped Ultraviolet Femtosecond Laser[J]. Nature Communications, 2026, 17: 973.
[29] 王京博, 曹利, 李松原, 等. Cu箔集流体飞秒激光深刻蚀织构化及其对锂离子电池性能的影响[J]. 表面技术, 2024, 53(1): 115-122.
WANG J B, CAO L, LI S Y, et al.Texturing of Cu Foil Current Collector by Femtosecond Laser Deep Ablation and Its Effect on Performance of Lithium-Ion Batteries[J]. Surface Technology, 2024, 53(1): 115-122.
[30] 李松原, 曹利, 王京博, 等. 锂离子电池NCM811厚膜正极飞秒激光织构化工艺研究[J]. 中国激光, 2023, 50(12): 1202401.
LI S Y, CAO L, WANG J B, et al.Femtosecond Laser Texturing Process for NCM811 Thick Film Cathodes in Lithium Ion Batteryies[J]. Chinese Journal of Lasers, 2023, 50(12): 1202401.
[31] WANG J B, CAO L, LI S Y, et al.Effect of Laser-Textured Cu Foil with Deep Ablation on Si Anode Performance in Li-Ion Batteries[J]. Nanomaterials, 2023, 13(18): 2534.
[32] LI Q S, SUN X F, ZHAO W Q, et al.Processing of a Large-Scale Microporous Group on Copper Foil Current Collectors for Lithium Batteries Using Femtosecond Laser[J]. Advanced Engineering Materials, 2020, 22(12): 2000710.
[33] WAN L, TANG Z J, YANG H H, et al.Achieving High Robust Laser Conduction Welding and Enhanced Joint Conductivity in Pure Copper Foil Stacks Using a Flat-Top Blue Laser[J]. Optics & Laser Technology, 2024, 174: 110701.
[34] OBROVAC M N, CHRISTENSEN L.Structural Changes in Silicon Anodes during Lithium Insertion/Extraction[J]. Electrochemical and Solid-State Letters, 2004, 7(5): 93-96.
[35] LIA J, DAHN J R.An in Situ X-Ray Diffraction Study of the Reaction of Li with Crystalline Si[J]. Journal of the Electrochemical Society, 1993, 140(4): 1173-1177.
[36] SHI F F, SONG Z C, ROSS P N, et al.Failure Mechanisms of Single-Crystal Silicon Electrodes in Lithium-Ion Batteries[J]. Nature Communications, 2016, 7: 11886.
[37] LI Q S, SUN X F, MEI X S, et al.Femtosecond Laser Fabrication of 3D Vertically Aligned Micro-Pore Network on Thick-Film Li4Ti5O12 Electrode for High-Performance Lithium Storage[J]. Journal of Energy Chemistry, 2024, 95: 250-262.
[38] LIU N, WU H, MCDOWELL M T, et al.A Yolk-Shell Design for Stabilized and Scalable Li-Ion Battery Alloy Anodes[J]. Nano Letters, 2012, 12(6): 3315-3321.
[39] WU X X, CHEN S J, LIU D N, et al.Polymer@Cu Composite Foils with Through-Hole Arrays as Lightweight and Flexible Current Collectors for Lithium-Ion Batteries[J]. Journal of Energy Storage, 2023, 74: 109208.
[40] CUI M, WANG L, GUO X W, et al.Designing of Hierarchical Mesoporous/Macroporous Silicon-Based Composite Anode Material for Low-Cost High-Performance Lithium-Ion Batteries[J]. Journal of Materials Chemistry A, 2019, 7(8): 3874-3881.
[41] KUMAR R, LU P, XIAO X C, et al.Strain-Induced Lithium Losses in the Solid Electrolyte Interphase on Silicon Electrodes[J]. ACS Applied Materials & Interfaces, 2017, 9(34): 28406-28417.
[42] GUO K, KUMAR R, XIAO X C, et al.Failure Progression in the Solid Electrolyte Interphase (SEI) on Silicon Electrodes[J]. Nano Energy, 2020, 68: 104257.
[43] PAN K, ZOU F, CANOVA M, et al.Comprehensive Electrochemical Impedance Spectroscopy Study of Si-Based Anodes Using Distribution of Relaxation Times Analysis[J]. Journal of Power Sources, 2020, 479: 229083.
[44] JIANG X Y, SHI X Y, YAO Y C, et al.Solid Electrolyte Interphase (SEI) for Silicon Anodes: From Evolution to Interface Engineering and System-Level Optimization[J]. Energy Storage Materials, 2026, 88: 105068.
[45] SZCZECH J R, JIN S.Nanostructured Silicon for High Capacity Lithium Battery Anodes[J]. Energy & Environmental Science, 2011, 4(1): 56-72.
[46] KIM H R, JANG Y J, SEO H, et al.Interface-Engineered 2D Si-Graphene Oxide Composite Anodes for Enhanced Li-Ion Storage Performance[J]. Journal of Alloys and Compounds, 2025, 1036: 182120.
Funding
Youth Beijing Scholar Program
PDF(5845 KB)
